The present invention relates to novel catalyst structures.
A catalyst is a material that converts reactants to product through repeated and uninterrupted cycles of elementary phases. The catalyst participates in the conversion, returning to its original state at the end of each cycle throughout its lifetime.
Currently, commercial catalysts for gas/solid, liquid/solid or gas/liquid/solid processes come in various shapes:                solid shapes (sphere, cylinder, trilobe, quadrilobe, tetrahedron, cube, octahedron, dodecahedron, icosahedron)        hollow shapes (cylinders or multilobes) either pierced by several convex holes of various shapes (circle, angular sector, lobe), or pierced by several non-convex holes such as the internal quadrilobe.        
For all these shapes, the hydrodynamics of the reactor is mainly due to the packing of the catalysts and not to their shape, that is to say that the fluid “slides” over the shapes without these shapes generating fluid ejection effects in order to increase the dispersion and the mixing within the bed.
The packing of the catalyst shapes according to the prior art is very porous, has a high void fraction percentage of the packing (PFVE) (>70%) and therefore generates fewer pressure drops. However, the hollow shapes (barrels or miniliths) based on a network of channels having symmetries, result in a packing that, statistically, has numerous preferential pathways. This leads to a low radial dispersion, little turbulence and therefore poor extraparticle material transfers (transfer of reactants) (i.e. transfer of gaseous or liquid phases to the surface of the catalyst), considering gas/solid, liquid/solid or gas/liquid/solid catalytic reactions.